1. Field of the Invention
The present invention relates to an improved apparatus and method for maintaining the purity of water used in an aquarium water recirculating system, particularly for salt water/reef and invertebrate tanks, including an improved protein skimmer for use in such an apparatus and method.
2. Description of the Prior Art
A main object of aquarium maintenance is to maintain the captive aquatic life in a state of health approximating that which would be enjoyed by the captive species in a normal existence outside captivity. One factor in achieving this goal is to control the population density of the life maintained within the aquarium. However, even with optimum population density within the closed loop system, during life cycle processes, dissolved proteinaceous compounds form from many sources within the tank including leftover food, aquatic life wastes, and decaying plants and animals. Environmental bacteria then break down these compounds into ammonia which is converted to nitrates and nitrites by other bacteria. All of these later compounds (NH.sub.3, nitrates, nitrites) eventually reach levels which will destroy the aquatic life unless steps are taken to control their level.
A variety of mechanical filters are known in the prior art which utilize, e.g., gravel, glass wool, diatomaceous earth, and the like to control the level of debris and waste materials in aquarium water. However, these devices suffer from the disadvantage of being unable to remove dissolved compounds from the aquarium water. Biological filters are also known in the prior art which utilize helpful bacteria (nitrosomonas and nitrobacters) which are, for instance, cultivated in the sand or gravel of the aquarium filter bed to convert ammonia to less toxic forms. This mechanism is described, e.g., in Fish And Invertebrate Culture, Water Management In Closed Systems, Steven H. Spotte, Wiley Interscience, 1970.
Protein skimmers have also been used in the past in the marine aquarium environment to control the level of toxic compounds in aquarium water by the technique of foam removal of dissolved protein compounds from the water. See, for instance, U.S. Pat. No. 3,965,007, issued June 22, 1976, to Conn et al.
In spite of these advances, the prior art filtration systems have suffered from a number of deficiencies. Subgravel biological filter systems typically lack sufficient surface area to effectively remove toxic substances from the tank water where any significant fish population exists. External biological filters have typically failed to effectively disperse the inlet water supply to the filter material in which the helpful bacteria are cultivated, thereby leading to the formation of dead spots within the external filter media. The protein skimmers used in the prior art biological filtration systems were typically configured as vertically oriented, hollow columns or chambers. As a result, the travel time of the air bubbles up the vertical column did not provide sufficient contact time with the water being treated to effectively remove dissolved protein materials from the aquarium water.
An object of the present invention is to provide a more efficient mechanical/chemical/biological filter to remove the main source of toxic compounds from aquarium water to prevent harm to the captive aquatic life maintained in the aquarium.
Another object of the invention is to provide an improved protein skimmer for use in such a system which provides improved foam separation for removing proteins, colloids and soluble high molecular weight compounds from aquarium water.
Another object of the invention is to provide an improved aquarium filter having chambers molded from synthetic materials which are long lasting and resistant to breakage.
Another object of the invention is to provide an apparatus which fits conveniently beneath most aquarium stands.
Additional objects, features and advantages will be apparent in the written description which follows.